There are known and commercially available a number of different designs of vehicles for handling and moving loads, especially loads on pallets, short distances. Vehicles commonly referred to as "forklifts" have been used for many years in numerous industrial and other applications. The forklift has a fork-vertical slide mechanism for engaging and lifting the load, and the moment of the load is offset by the counter-moment of the vehicle. The axle of the front wheels of the forklift provides the fulcrum in both the stationary-load position and the dynamic-carry mode. By tilting the mast containing the fork-slide mechanism, the moment of the load is reduced somewhat, but a substantial counterweight is still required, and the forklift cannot carry a load in excess of its own weight.
There is also known and commercially available a material handling vehicle which can lift and carry loads in excess of its own weight. This vehicle has a variable wheel base provided by a design that permits the front wheels, which are mounted on "legs", to be extended as the load is lifted and carried. The rear wheels or wheels can also be extended or withdrawn. In this manner, the lifting moment is eliminated since the load will be between the front and rear supporting wheels. Thus, there is no necessity for a counterweight. However, with this vehicle, the load must be lifted and carried between the front wheels thus limiting the use of the vehicle to those situations where space permits the vehicle to travel with a wide stance. Also, because of the mechanism required for extending and withdrawing the wheels, the vehicle is relatively expensive.
There is therefore a need for a material handling vehicle that is capable of lifting loads in excess of its weight and which is small enough in physical size to be useful in applications where space is limited. There is also a need for a relatively inexpensive material handling vehicle that can carry loads comparable to the standard forklift in industrial applications where space is limited and also in other applications as well.